Preheat oven to: 375 degrees (F)
From the Food52 link: Place a rack in the center of the oven and preheat. Generously grease a 12-cup muffin tin.
In a large bowl, stir together the flour, sugar, baking powder, baking soda, and salt.
Add the cold, cubed butter and press it into the flour with your fingers until the mixture looks like coarse sand, with no large butter clumps left. Work quickly so the butter stays cold.
Stir in the raisins, then drizzle in the buttermilk and cream.
Gently scoop the dough into the muffin tin, dividing it evenly between the 12 cups.
Whisk the egg yolk with 2 tbsp heavy cream and brush over each scone.
Bake until golden brown and a toothpick inserted into the center comes out mostly clean, 22-25 minutes.